In the case of a hydrogen fuel cell system, a fluid control valve is installed in a high-pressure vessel in which a source gas is stored, and controls flow of the source gas when the source gas is charged into a high-pressure vessel, and also controls flow of the source gas when the source gas stored in the high-pressure vessel is supplied for a gas consumer such as a gas engine.
The fluid control valve can precisely control flow of the source gas according to electrical signals, need to maintain a constant pressure of a fluid stored in a pressure vessel, and need to prevent an explosion of a high-pressure vessel when a hydrogen fuel cell vehicle rolls over or a fire breaks out in a hydrogen fuel cell vehicle.
As disclosed in U.S. Pat. No. 7,309,113 B2 (Dec. 18, 2007), a conventional flow control system for a valve includes: a valve body mounted in a high-pressure cylinder and having a main flow passage connecting a first area at a first pressure to a second area at a second pressure; a filter that is mounted at an inlet side connected to the main flow passage; a manual valve that is mounted at a portion communicating from the main flow passage and that manually opens and closes the main flow passage; a solenoid valve that is mounted on a backpressure passage communicating from the main flow passage and that opens and closes the backpressure passage in accordance with an electrical signal; and a shuttle valve that is mounted on the main flow passage and that closes the main flow passage if an over-pressure occurs and opens the main flow passage if a normal pressure is generated.
In such a conventional flow control system (bra valve, a high-pressure charging gas flows into the main flow passage through an inlet of the valve during charging, and passes through the solenoid valve if the solenoid valve operates in a direction where the solenoid valve is open to then flow into the high-pressure cylinder. In addition, when a source gas stored in the high-pressure cylinder is supplied to a gas consumer such as a gas engine, the source gas stored in the high-pressure cylinder passes through the backpressure passage to then be supplied to the gas consumer through the inlet of the valve via the solenoid valve.
However, in the case of the conventional flow control system, since the high-pressure charging gas is directly applied to the solenoid valve, the durability of the solenoid valve may decrease and a malfunction of the solenoid valve may occur. Further, as duration of use of the conventional flow control system becomes longer, the solenoid valve may be damaged.